The present invention relates to a temporary structure used for shelters or the like and/or relates to a structure used in containment systems wherein an object, building or other structure is sealed to the environment to contain airborne contaminants, and relates more particularly to such a structure wherein the components thereof are capable of being readily assembled without need of numerous bolt connections and the requisite tools required for such assembly.
The formation of supporting structures for temporary shelters and/or containment enclosures inherently need to be both lightweight and capable of withstanding the loads imposed by elements, such as, wind, rain, and snow. Because these structures are usually covered with air impermeable sheathing, they are subjected to the same loading conditions experienced by a building. Wind loads are a major design factor and concern with such structures. This is because these structures have very expansive surface areas which are exposed to wind forces. Therefore, the structure which supports the enclosing sheathing must have sufficient strength to withstand these applied loads. In addition, such structures should also be preferably formed from a lightweight material which would allow it to be readily handled by workers. In the past, the supporting structures were fabricated from preformed building elements which required a multiplicity of bolting connections as between vertical support members, horizontal trusses and bracing or purlin members. Such connections require numerous man-hours in the assemblage of the structure, given that each connection must be secured by virtue of bolting the members together. It is also desirable to provide building elements of a type which have a low linear weight which allows for longer unsupported spans and requires less substantial vertical supports. The aspect of providing lightweight members has further importance in that it allows for the entire structure to be lifted, for example, by a crane and lowered into place over a desired footprint or a structure to be contained. Additionally, such structures must be capable of readily attaching a protective covering or sheathing to the underlying structure. In the past, it was known to use fixing timbers which were separately attached by clamping to the structure at points along the individual truss members. The sheathing was then attached to the truss structure by nailing it to the wooden fixing members. The problems attendant to these known fixing systems were that the fixing members were heavy and cumbersome, and added unwanted weight to the structure. Additionally, the securing of the wooden fixing beams to the truss structure involved additional labor which added time and, hence, cost to the project. Also, it is important to maintain the uniform spacing of the truss members so that a predictable arrangement of truss members can be fabricated. This is because when the securement points are oriented at uniform spacings, it is easier to secure the sheathing to the underlying support structure when the location of these points are known.
Accordingly, it is an object of the present invention to provide a supporting structure comprised of a plurality of standardized structural elements which are assembled together without the heretofore known use of bolting connections existing as between bracing and truss members and to provide a structure of such construction which allows numerous components of the structure to be assembled by a drop-in-place joint design.
It is a further object of the invention to provide individual structural elements of a standardized form useable together in a supporting structure made up of a plurality of such standardized structural elements configured to provide spans which have high bending strength and which deliver very high strength to weight ratios.
Still a further object of the invention is to provide a supporting structure which is modular in construction as defined by individual elements of predetermined and standardized constructional form having connections which allow successive repetitions of structural segments to be created along a given span of a truss.
Still a further object of the invention is to provide a supporting structure of the aforementioned type wherein the standardized structural elements each has a means for readily connecting it to sheathing material at infinite locations taken along its length.
Other objects and advantages of the present invention will become apparent from the following description and the appended claims.